Means for generating high-frequency currents



March 30 1926. 1,578,258

A. BLONDEL ET AL MEANS Fox GENERATING HIGH FREQUENCY cuRRENTs 'n D' E Ta I wmf B10/m51,

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March 30,1926. n 1,578,258

A. BLONDEL Er AL MEANS FOR GENERATING HIGH FREQUENCY GURRENTS Filed May 18, 1921 l 2 Sheets-Sheet 2 f7 Aff/JM Mamani? liatentedMar. 30, 1926i'.v

yU'NiTED ',"STAT.es

vAimar?. BLONDEL, 0E PARIS, AND MARCEL ToULY', oE starcLoUD," FRANCE.

vlVIEANS FOR GENERATING HIGH-FREQUENCY CURRENTS.

Applcationled May 18, 1921. Serial No. 470,598.

To all 'whom it may concern. V*Be `it known that we, ANDR BLONDEL,

citizen of the Republic of France, residing` at Pari's,'in the Republic of France, and

@This linvention relates to a method Yand means forgeneratinghigh frequency cui7 rents in which a'system ofy valves coupledv togetherare used for the generation of continuous waves vfor wireless telegraphy and the modulation of these waves for Vwireless telephony.

The valves connected in parallel 'servefto set up waves in an' antenna circuit and an-y other weaker valve or group of valves vserves to excite the main valve by acting on its grid. Additional tiers of valves may be added if desired. I

.- The dili'erent valves or groups of valves are connected in such a manner that any one, separately, could not set up persistentoscillations,4 inthe antenna, lsimultaneous action of twovalvesor groups ofvalves operating by mutual coupling being necessary for this purpose;

IVIn telephony Va microphone mayact by mutual induction or by ,a branch-connection Y by capacity onone of the members of the system of either of tlie valvesin-orderto detune one of the oscillating circuits or to 'causel a variation in the degree of coupling. Under some circumstances a reaction is added between the inductance of the antenna and the grid of 'one of the valvesto diminish the-damping ofthe antenna. It is to be understood, however, that suoli reaction must be lrept within certain limits wherein the said reaction Vis insuflicient to `giif'e rise, by

itself tofoiscillations in the antennae.

In the drawingsherewith:

Fig. l shows the general principles ofthe invention indiagrammatic form.

tem with three tiers of valves.'

Fig. 3 is a diagrammatic view of the System with a special device for improving the modulationv process. and 'obtaining a more powerful action by a microphone.

v Fig. 4; shows `the application of the system in a transmitting 'station-forrsuse 'in c'onnecf tion with alternating'current. i

Fig. 5 shows a wireless telephone station with duplex connections utilizing theprin# ciples set forth in the preceding iigures. v

In the drawings the following reference letters ,are'usedz---r A1V 'ndicates `a relay valve.

A2 indicates a working valve.

G indicates a grid. y

P indicates a plate.

L indicates an inductance.`

C indicates a condenser..y

La andCa indicate theinductance'and ca.-v

pacity of the antenna.

.B indicates abat-tery.

f Bc indicates. a heatingibattery; i indicates a battery for! making" the grids negative. f

5 t indicates a transformer. T is an earth-connection. y is a coupling pedance. .1 l y Y Z is the impedance of the coupling. c

" "1 is a rheostat-in the heating circuit ofthe- .R is a large'` resistance to static charges.`

condenser of small iin vLm is a .mutual induction winding. i .L i

Ml is a microphone..` Bm is amicrophone battery.

modulation.

Al andV A2y are differential valves for Arrows `across a condenser or winding i showthat-.they are adjustable.

lInA .the installations Ashown herewith rheos'tat oi`.liigh resistance'has beenxpi'ovided for discharging in the usual manner, the

grids on the filamentsso as to prevent their taking too heavy negative. charges during the oscillations. In some cases,4 thisrheostat may be vreplaced by the internal resistance v i but .ifv desired, for telegraphicpurposes ya Fig. 2 is a diagrammatic view of the sysf signalinglrey coul-d 'be substituted forpthe so that transmission. is interrupted' by the closing kof the signaling key. In-soine lforms theworking valve and itsoscillating circuit aie made dependent .on `the switchandthe relay valvecr group has a power equal to the losses occurring in the grid circuit-- ofV the Valve'or valves. s It is 'desirable to reduce .l the current given "by the microphone.

antenna inductance.

Y In Fig. l the Y 'system is shown with the grid of the Vworking valve A2 coupled through the "plate inductance Lm withythe The saidV valve. and its circuit maybe adjusted slightly below the point of oscillation. V'By modulationy of the circuit through'th'e intermediary-of a microphone connecte'dat M to induction coil Lm, the Vcircuit may lbfeset into a state of voscillation.

Y InafFig. 2 lis shown` anarrangement with two'relay valves arranged in Acascade-the connection between 'valves'A1 and A, being madeY through `the 7circuit L C, and the 'connectionV between the relay valve-A1 and .A2v being made through the Vtransformer T. The dampingofzthe antenna is reduced by the reaction of theircapacity C0,.-the work-v ing valves being arranged slightly below the point of continuous 'oscillation andthe microphone M beingcoupled to the fcscillaf.V

tory circuitth-rou'glra condenser 3C.r n

of two relay valves in cascade, fasQfor-high' power stations several valves could lbe used either in cascadef-or infparallel-or in cascade-parallel, the l.connections between the valves consisting of any of the usual'knownl means. ,Y

f There'action for the :reduction of the damping may be produced between thefplate circuit and xthezworking valves and any one of the relay valves. Tofeifectthis vbetween the antenna and the first-valvefthe left hand plate of the condenser 'Gais connected to xthe gridfof A11 To reduce the dam-pingby the `,action of the grid. of A1, a mutual induction coil' (notV shown) Vcould `be' introfducedr between the'ftwo .peints a land b of the circuitofftfhe fsaid :grid (Fig. 2) which coil Y Vis arranged :asV is Lm in close :proximity tol 'y coupled vvalve generator. l

qu'ency generator (not shown) induces in the inducta-nce La 'so Vas to obtain :ax suitable phase. v

' lnfFig. vSirtherepisshown vasystem in which a :microphone facts-'as a. modulator v.in ra The high Vfre- 65" fequfalfby the Contact K connectedfto the bat-` tery alongthe rlieostatY r', A'and thereby the ters, cil-a? and a3. *i i 1 'This invention is not limited to -the use `v currents may be equalized when there is no-A speech' into Ithe microphone.

In Fig. i the system:'sliown .inay'beused in a transmitting.stationthe tubes `being for use in connection'with alternating current. A11 is the relay valve, A2 is the working` valve, L1,`L2, 'L3 and Lt are' inductance's, T is the ground, y2 is acoupling condenser of small impedance, R? is a resistance to static charges, t1, t2, t@ are transformers, and C1 and C2 are condensers.

A duplex arrangement lfcr wirelesstelegf raphy'jis shown in Fig.v .5, the knownigene-rating yandmodulating arrangements :being Y represented by rectangles, and the rgure showing how they act on agenerator :with

three amplifying stagesA in ,which vthe ,Ife-l t'urn action acts on the grids of the second tier ofvalves. D is a. 'small generatorfofthe usualjtype; M is aimodulatorgf A1 kis'airell'ay valve whose vgrid 'is Yacted 4upon :by ithev Said ersk modulator, and A2 is a group offvalves parallel and forming :asecond amplifying stage, YandfA3 is ,a'second group ofi-more powerful valves :arranged ;1n yparallel :and

no i' constituting -a third stage oflargefoiitp'ut.

Three valves of a yhigh and, lowff'requeney amplifier are indicated by the 1re-ference letkvXVe clainm- 1. inthe generation of nhigh frequencyalternating currents for radio signaling jby means of Atherinionic tubes, twothermionic units comprising a power :or working `unit and a relay unit, the working unit ibe'ing ico first adjustedinV a nearly oscillating condi i tion lby retroactively coupling itsignputfand output circuits and' the vstatenl of Xoscillation being then obtained -byijcnce mcreretroactively 'coupling the samecircuitsfithrough the relayunit. Y y

2. A lhigh frequency vacuumk tubefgen- 'i mionic unit connected :ther-etc, va rrelay @thermionic unit with its outputcircuit :ccn-

erator comprisingin combination, an oscill-ating Vcircuit, a-ypower Vorwerking ,ther-`V r nected totheinputc-ircuit of the-sai'duwork- Y ing unit, means 'for retroactively .coupling the inputfand output circuit ofthe firstunit through the second one, Yof an -amou'ntzisuflicient to keepV the system oscillating and means for varying thesaidainount iaccording tothe rhythmof--signa-ls. Y

erator ycomprising Vin 'combination van oscillating circuit, a power 'or working ther? said 'f unit vof linsufficient .magnitude l`tov-keep the unit oscillating, a vrelay lunitrthe out-,put

3. .AQ high frequency vacuum ftube, gen;

circuit of which is connectedfto the :input circuitofy the saidworkingiunit, asecond reaction lcoupling' between theioutputffa-nd 'input circuits of the working unit 'through anvaniount sufiicient to 139 i Vary keep the systemjosoillating andmeans' to'V Ythe said second reactlon coupling ac#- cording to the rhythm offsignals.

v 4. A high frequency vacuum tube kgen-V erator comprising n combination an oscillat-U ing circuit, a power or Working thermionic unit, connected thereto, ksaol unit consisting in a Vacuum tube 2L rst reaction coupling be- .tWeen the circuits of the saidv unit, of a magnitude insuioient to bring the unit into oscillation a relay unit, the output circuit of I which is connected to the input oircuit of the y v betweenthe input and'output rcirouitfofthe working unit through the relay unitfof a oillating and means to vary the said' second t y Armen BLONDEL. f MARoELToULY.

vreaction coupling according to the rhythm of signals. y

'In Witness whereof We'fhave hereunto 20 signed. our names this 3rd day 'of May 1921.

l magnitude suiicent to keep the system os-iY 

